go-actor

go-actor is tiny library for writing concurrent programs in Go using actor model.

Motivation

This library was published with intention to bring actor model closer to Go developers and to provide easy to understand abstractions needed to build concurrent programs.

Examples

Dive into examples to see go-actor in action.

// This program will demonstrate how to create actors for producer-consumer use case, where
// producer will create incremented number on every 1 second interval and
// consumer will print whaterver number it receives
func main() {
	mailbox := actor.NewMailbox[int]()

	// Producer and consumer workers are created with same mailbox
	// so that producer worker can send messages directly to consumer worker
	pw := &producerWorker{outC: mailbox.SendC()}
	cw1 := &consumerWorker{inC: mailbox.ReceiveC(), id: 1}
	cw2 := &consumerWorker{inC: mailbox.ReceiveC(), id: 2}

	// Create actors using these workers and combine them to singe Actor
	a := actor.Combine(
		mailbox,
		actor.New(pw),

		// Note: We don't need two consumer actors, but we create them anyway
		// for the sake of demonstration since having one or more consumers
		// will produce the same result. Message on stdout will be written by
		// first consumer that reads from mailbox.
		actor.New(cw1),
		actor.New(cw2),
	)

	// Finally we start all actors at once
	a.Start()
	defer a.Stop()

	select {}
}

// producerWorker will produce incremented number on 1 second interval
type producerWorker struct {
	outC chan<- int
	num  int
}

func (w *producerWorker) DoWork(c actor.Context) actor.WorkerStatus {
	select {
	case <-time.After(time.Second):
		w.num++
		w.outC <- w.num

		return actor.WorkerContinue

	case <-c.Done():
		return actor.WorkerEnd
	}
}

// consumerWorker will consume numbers received on inC channel
type consumerWorker struct {
	inC <-chan int
	id  int
}

func (w *consumerWorker) DoWork(c actor.Context) actor.WorkerStatus {
	select {
	case num := <-w.inC:
		fmt.Printf("consumed %d \t(worker %d)\n", num, w.id)

		return actor.WorkerContinue

	case <-c.Done():
		return actor.WorkerEnd
	}
}

Contribution

All contributions are useful, whether it is a simple typo, a more complex change, or just pointing out an issue. We welcome any contribution so feel free to open PR or issue.